drm/xe/pm: Add vram_d3cold_threshold Sysfs

Add per pci device vram_d3cold_threshold Sysfs to
control the d3cold allowed knob.
Adding a d3cold structure embedded in xe_device to encapsulate
d3cold related stuff.

v2:
- Check total vram before initializing default threshold. [Riana]
- Add static scope to vram_d3cold_threshold DEVICE_ATTR. [Riana]
v3:
- Fixed cosmetics review comment. [Riana]
- Fixed CI Hook failures.
- Used drmm_mutex_init().
v4:
- Fixed kernel-doc warnings.
v5:
- Added doc explaining need for the device sysfs. [Rodrigo]
- Removed TODO comment.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718080703.239343-4-anshuman.gupta@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 7a62c54939a9..14b15ecc5617 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -327,11 +327,27 @@ struct xe_device {
 		bool hold_rpm;
 	} mem_access;
 
-	/** d3cold_capable: Indicates if root port is d3cold capable */
-	bool d3cold_capable;
+	/** @d3cold: Encapsulate d3cold related stuff */
+	struct {
+		/** capable: Indicates if root port is d3cold capable */
+		bool capable;
+
+		/** @allowed: Indicates if d3cold is a valid device state */
+		bool allowed;
 
-	/** @d3cold_allowed: Indicates if d3cold is a valid device state */
-	bool d3cold_allowed;
+		/**
+		 * @vram_threshold:
+		 *
+		 * This represents the permissible threshold(in megabytes)
+		 * for vram save/restore. d3cold will be disallowed,
+		 * when vram_usages is above or equals the threshold value
+		 * to avoid the vram save/restore latency.
+		 * Default threshold value is 300mb.
+		 */
+		u32 vram_threshold;
+		/** @lock: protect vram_threshold */
+		struct mutex lock;
+	} d3cold;
 
 	/* For pcode */
 	struct mutex sb_lock;